1. Field of the Invention
This invention relates generally to calculators, and more specifically, to a calculator capable of recognizing handwritten input.
2. Description of Related Art
At times, nearly everyone still uses scratch paper to perform manual calculations. These are skills that are taught at an early age. Typically, a person writes the numbers on the paper in a horizontal arrangement with an equal sign: EQU 111+222=333
Alternatively, the person writes numbers on paper in a vertical arrangement with decimals aligned and a line underneath: ##EQU1##
The person does the calculation manually using techniques learned early in life, and then writes the result (which is sometimes wrong) below the line or to the right of the equal sign. If more calculations are required using the result, then the person places them near the result to avoid writing twice. Some information may be left off the paper. The person can copy numbers from one part of the paper to another. The paper remembers everything done, and displays the whole calculation. With sufficient training or tools, anyone can do any mathematical operation.
Because of the drudgery involved and because of the real possibility of errors, many calculations are performed with calculators. Calculators are typically mechanical or electric devices. Electronic calculators are fast and accurate, and the advent of integrated circuits have provided more powerful calculators capable of sophisticated functions, including programmable calculators. Today, calculators cab be specialized for particular applications including basic engineering, scientific or statistical applications.
Unfortunately, as calculators become more powerful and capable, they become harder to use. Often, function keys on the calculator may represent two, three or more functions. A person has to read and understand a thick reference manual in order to use the calculator. No wonder people may believe you need a Ph.D just to operate the calculator.
The present invention takes the concept of a calculator in a full circle back to its beginnings, i.e., the use of scratch paper. The present invention simulates a "smart pad" of scratch paper capable of performing calculations that a person handwrites in a natural notation. The present invention recognizes all types of calculations and mathematical functions, thereby providing the same capabilities as the most powerful calculators.